Dome Pistons and spark plugs - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 11-02-2006, 11:27 AM
DeathRattle's Avatar
Some Punk Kid
 
Last photo:
Join Date: Oct 2006
Location: Michigan
Age: 27
Posts: 787
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Dome Pistons and spark plugs

While adjusting the rockers when I was looking for TDC I noticed the dome of the piston was what seems like very close, which leads me to my question. Will any plug clear it or should I be looking for a plug with a specific reach and thread length. First engine build with dome pistons so I am not sure of myself on this. Thank You for any replies regarding my question.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 11-02-2006, 12:07 PM
Known traffic menace
 
Join Date: Aug 2006
Location: Hohenwald Tn.
Age: 57
Posts: 82
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
DeathRattle, Need a little more info. Engine, Heads, Pistons. Perry.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 11-02-2006, 12:55 PM
DeathRattle's Avatar
Some Punk Kid
 
Last photo:
Join Date: Oct 2006
Location: Michigan
Age: 27
Posts: 787
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Engine 1970 Impala 2 bolt 300 horse block
stock crank and con rods
Pistons-Speed Pro
Bore (in): 4.040 in.
Bore (mm): 102.616mm
Piston Material: Forged aluminum
Piston Style: Dome
Compression Distance (in): 1.560 in.
Dome Height (in): 0.213 in.
Piston Head Volume (cc): -10.60cc
Valve Reliefs: Two

Heads are used GM stockers. The engine shop says they are either 72cc or 76cc. I believe they are 76cc. If you want casting numbers I can get them. I just asked for heads they had around the shop nothing special. They put in new valves and the comp cam springs I bought. The guy I bought the engine from had camel back heads on the engine. But I am not sure if 70 impalas still had camel back heads. Any way I did not buy them as i want to hang accessories.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 11-02-2006, 02:39 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 37
Posts: 4,078
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
You kinda have to know the what head yuo got. My best guess say's you won't have problems with those big chambers. You should check anyway.

The head will usauly dictate what plug you'll need. It's probably a 14mm, 3/4 reach.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 11-02-2006, 04:04 PM
DeathRattle's Avatar
Some Punk Kid
 
Last photo:
Join Date: Oct 2006
Location: Michigan
Age: 27
Posts: 787
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Alright, thanks for the advice. Ill go out and buy some cheap cold or medium heat 3/4 reach plugs and see what happens when I spin by hand and when I fire it up for the first time.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 11-04-2006, 05:40 PM
DeathRattle's Avatar
Some Punk Kid
 
Last photo:
Join Date: Oct 2006
Location: Michigan
Age: 27
Posts: 787
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
They are 3998993 hencho's. mortec says they are goodwrench crate motor heads. 75cc chambers. Havent got the 3/4 plugs yet as I need to readjust my rockers with a new technique. The engine manual says to use the twist pushrod method instead of the up and down jingle method when adjusting rockers. My cousin says using the twist method could bind up the lifter internal spring. He says I should check them and see if I had them too tight as If I started engine like that i could screw up the tappets.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 11-04-2006, 08:22 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,564
Wiki Edits: 326

Thanks: 697
Thanked 877 Times in 745 Posts
"My cousin says using the twist method could bind up the lifter internal spring."

Having been there, done that, I agree with your cousin.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 11-06-2006, 11:46 AM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 37
Posts: 4,078
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
Try the AR 133 for that head in a short style or a R45TS ACdelco for the long ones.


It's very hard to tell when the lifter spring is being pushed down. Take extreme care and pay close attention. Wiggling up or down with a very light touch is best.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 11-06-2006, 04:06 PM
DeathRattle's Avatar
Some Punk Kid
 
Last photo:
Join Date: Oct 2006
Location: Michigan
Age: 27
Posts: 787
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
I re-did the rockers. Majority of them were too tight on the lifters. Problem with them spinning method is the lifter will spin with rod as you tighten it down until spring is smashed all the way down. I cannot believe this is the method adopted by the author/publisher of the small block chevy book(HPbooks). The jiggle up and down method was by far smoother and it allowed for proper gap between rocker and stem when you push down on the rod side of rocker.

P.S.-Johnsongrass1 can you take a peak back at my other thread again. 2 bolt RPm and power. Its a couple pages back already. I am really lookin for a lot of opinions on this motor.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Spark plug recommendation for 6-71 SBC XNTRCI-T Engine 4 04-11-2006 09:20 AM
Two Dead Pistons??? Question For The Expert!!! mike65 Engine 71 04-08-2005 10:02 AM
SBC Spark Plug Suffix Question. FBody Electrical 1 09-07-2004 03:27 PM
correct spark plugs for nitrous davidwobken Engine 1 07-19-2004 05:18 AM
87 Camaro/no spark 77sleeper Electrical 7 06-14-2004 12:50 AM


All times are GMT -6. The time now is 02:28 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.